Oil reserve tanks store oil used for various types of engines, industries, etc. When water or particulate contaminants are mixed in oil, the impure oil is likely to cause malfunctioning of machines.
Moreover, when oil containing water is supplied to an engine, the water in the oil corrodes parts of the engine, causing fatal damage to the engine, leading to start failure or abrupt stopping of the engine.
To this end, a conventional water removal system for removing water from oil is disclosed in Patent Document 1. Patent Document 1 is Japanese Patent Application Publication No. 2003-34400 titled “Drain Detector for Oil Reserve Tank”.
The drain detector disclosed in Patent Document 1 includes a level sensor that is installed on the bottom of an oil reserve tank and a display unit that is electrically connected to the level sensor. The display unit is installed outside the oil reserve tank.
According to the conventional drain detector, when drain water gravitates toward the bottom of the oil reserve tank and reaches a level at which the level sensor is mounted, the level sensor detects the level of the drain water and sends a signal to the display unit. In this way, the drain detector issues a warning.
When an operator recognizes this warning, the operator opens a valve on a drain pipe to discharge the drain water outside the oil reserve tank.
The drain detector disclosed in Patent Document 1 features the arrangement in which the level sensor is mounted on the inside bottom of the oil reserve tank. However, since the level sensor is not fixed in place on the bottom of the oil reserve tank, sometimes the level sensor cannot accurately detect the level of the drain water. In this case, the level of the drain water cannot be reliably measured.
In addition, since the level sensor is submerged in oil in which water or contaminants are mixed, the level sensor is highly likely to be contaminated. The contaminated level sensor cannot be replaced or cleaned until the oil is completely discharged outside the oil reserve tank.
For this reason, there is the demand for solving this problem.